There is no more gap on the back on the neck for some other armors than Cage or Spike armor.
You need AWKCR and Armorsmith Extended and this mod must be loaded after these 2 mods.
There are 2 version: brown vanilla and black.
You can craft them in Armorsmith Workbench under HeadGear category.
just do that mumbo jumbo as you do to install mods in Fallout4.
thanks to
Gambit77 for Armorsmith Extended
valdacil for AWKCR
Bethesda for Fallout 4
ElminsterAU for FO4Edit